Suprapubic catheterization of the bladder is used to drain the bladder after surgery or when the genitourinary system is plugged by an obstruction. Other percutaneously inserted catheters are also used to drain the kidney or biliary system as well as to drain abscesses, other sites of fluid collection, and other viscera. Still other percutaneously inserted catheters are gastrostomy feeding tubes.
These catheters are typically introduced into the patient by means of a large hypodermic needle or trocar, which pierces the abdominal wall. A wire guide is inserted through the needle and then the needle is removed. The catheter tube with a stiffening cannula positioned therein is then passed over the wire guide into the cavity. The cannula and wire guide are withdrawn, leaving the catheter in the desired cavity. In addition, a dilator and an access sheath may be used alone or in combination with one another over the wire guide to increase the size of the puncture site before passing the catheter tube over the wire guide. With respect to the bladder, the advantage of this technique is that irrigation and infection of the urinary tract is minimized. However, one problem with these catheters is that the catheter can be easily pulled out by movement of the body or by the emptying of, for example, the bladder. Another problem is that side ports at the distal end of the catheter may be inadvertently drawn into the abdominal cavity, creating the potential for severe infections.
Various catheters have been developed with so-called pigtail loops at their distal ends for ensuring drainage of the cavity and preventing accidental removal therefrom. The pigtail loop is tightened by pulling on the proximal end of a flexible tension member, which extends through the catheter. The proximal end of this tension member is held in place by any one of a number of retention means. One known locking drainage catheter includes a lockable connector positioned about the proximal end of the catheter. The catheter also includes a flexible tension member that extends through the lockable connector for drawing the distal end of the catheter into a loop. The lockable connector includes a resilient material sleeve with a sleeve passage extending longitudinally therethrough for positioning the tension member therein. The sleeve is positioned in a passage of the connector adjacent a channel, wherein a pivotably attached lever is positioned. When the lever is pivoted toward the connector into a fixed position, a cam surface of the lever compresses the sleeve and locks thereabout to maintain the loop formed in the distal member end. Although the locking drainage catheter is well-suited for its intended purpose, the lockable connector portion of the catheter is somewhat bulky, which may make the device somewhat uncomfortable for a patient and which prevents the device from being used with relatively smaller sized access sheaths (e.g., a 30 Fr access sheath) unless the access sheath is altered or modified. It is desirable to provide a locking mechanism for use with a catheter, such as a drainage catheter, that overcomes the disadvantages present with available catheters and locking mechanisms.